See-through jelly like substance shader
I tried SSS at first but was not happy with the results. I decided a glass shader looks much better. 

I just used a Principled shader with transmission set to 1, for glass. Then I added some volume scatter with a slight orange color just so it doesn't look like glass and has some volume in the inside. 

I did not do it here but I think slightly deforming the spheres will give it some more realism.